Air-Gap Formation in Interconnect Structures
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsCheng-Hsiung Tsai, Chung-Ju Lee, Tien-I Bao
Life of this patent
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Abstract
A structure includes a substrate, and a first metal line and a second metal line over the substrate, with a space therebetween. A first air gap is on a sidewall of the first metal line and in the space, wherein an edge of the first metal line is exposed to the first air gap. A second air gap is on a sidewall of the second metal line and in the space, wherein an edge of the second metal line is exposed to the second air gap. A dielectric material is disposed in the space and between the first and the second air gaps.
Claims20
A method comprising:
- forming a conductive region;
- etching the conductive region to form an opening in the conductive region;
- forming a decomposable layer comprising a top portion over the conductive region, a sidewall portion on a sidewall of the conductive region, and a bottom portion at a bottom of the opening;
- etching the decomposable layer to remove the top portion and the bottom portion of the decomposable layer, wherein a remaining portion of the decomposable layer forms a decomposable spacer on the sidewall of the conductive region;
- forming a low-k dielectric layer in a remaining portion of the opening;
- and
- decomposing the decomposable spacer to form an air gap.
A method comprising:
- etching a first dielectric layer to form a via opening;
- forming a conductive barrier layer comprising a first portion over the first dielectric layer, and a second portion in the via opening;
- filling the via opening with a conductive material to form a via in the via opening, wherein the conductive material comprises a portion overlapping the first portion of the conductive barrier layer;
- patterning the conductive material, wherein remaining portions of the conductive material form a first metal line and a second metal line spaced apart from each other, with the second metal line overlapping and joined to the via;
- forming a dielectric barrier layer on top surfaces and sidewalls of the first metal line and the second metal line;
- forming decomposable spacers on the sidewalls of the first metal line and the second metal line;
- forming a second dielectric layer filling a space between the first metal line and the second metal line;
- and
- decomposing the decomposable spacers to form an air gap.
A method comprising:
- forming a first metal line and a second metal line:
- forming a dielectric barrier layer on top surfaces and sidewalls of the first metal line and the second metal line;
- forming a decomposable layer over the dielectric barrier layer;
- etching the decomposable layer to form a first and a second decomposable spacer encircling the first metal line and the second metal line, respectively, with the first and the second decomposable spacers separated from each other by a space;
- forming a dielectric layer comprising a portion filling the space;
- and
- decomposing the decomposable spacers to form an air gap.
Dependencies are inferred from the claim text.